Dental crowns have been utilized for many years to provide protection to teeth that have required substantial, but not complete, removal due to various problems, such as the development of deleterious cracks at the subject tooth surface. Without removal of the affected tooth portion, the chances for bacterial infection (and thus invasive dental caries) within the outer tooth portion may create further complications that would consequently lead to extensive dental repairs. Additionally, the entire removal of the affected tooth could lead to expensive bridge or implant work that, furthermore, could be rather cumbersome, if not painful, at least initially, to the target patient. As well, the potential for root damage or destruction without proper treatment of an affected tooth may create highly painful circumstances for which the patient would require invasive dental repairs to overcome. As such, a dentist has typically adhered such a metal and/or ceramic crown directly over an affected tooth or, alternatively, has ground down an affected tooth until a residual post remains of sufficient size and strength to receive and retain (again with the aid of adhesives) crowns of similar materials. In such a manner, the patient may enjoy the retention of the base tooth, while also having the benefit of an artificial implement that is properly molded to fit in complementary fashion to the remaining tooth structure, as well as to provide the same shape (and sometimes, color) as the removed tooth portion from an outward appearance. Crowns have been perfected to the point that proper occlusion of such structures may be configured as closely to that of the original tooth in relation to the adjacent teeth in order for the target patient to, again, enjoy substantially the same benefits of the look and function of the prior tooth. Hence, dental crowns have become a standard and effective replacement for affected teeth without the necessity of full tooth removal and thus potentially more cumbersome and/or expensive alternatives.
One significant downside to crown technology, however, is, basically, the lack of transparency for a dental professional to have a proper vantage point to visibly examine the underlying tooth throughout the time such a crown is present. In other words, although a crown will provide a certain degree of protection to the underlying post, there still exists a definite possibility that undesirable bacteria or other microorganisms may penetrate underneath the crown and its adhesive layer (covering the subject tooth post) (or, alternatively, may have resided on or within the covered tooth surface prior to crown implementation) and begin to cause demineralization and/or adhesive decomposition as a result. In such a situation, without any capability to properly analyze the underlying tooth for any such problems, the dental professional would have no effective way of assessing the tooth status in terms of potential decay or other loss in tooth and/or crown integrity. If the tooth suffers from dental caries, for instance, the crown may lose its adhesive potential to the tooth surface as such a surface would potentially deteriorate over time, effectively altering the post structure upon which the crown has been situated. Additionally, beyond the potential for crown movement or loss, the underlying tooth may, without proper therapeutic action taken to disinfect and/or reverse such a caries problem, suffer a loss of stability itself, which may lead to tooth decay outright, or even to destruction or, at least, compromise some extent of the root. In any event, the results of such undesirable underlying tooth caries would undoubtedly lead to far more expensive, cumbersome, and potentially painful results for the target patient. Avoidance of such end results would thus be of great interest to the dental professional as knowledge of underlying tooth decay of such sort would at least provide an avenue for treatment to be undertaken. As it stands today, however, there are no effective measures available for detection of sub-crown tooth decay to overcome such an institutional deficiency.
Generally speaking, within the dental field, caries is defined as the progressive decay of tooth or bone. Dental caries, itself, may be treated through the removal of decayed (or decaying) material in the subject tooth and filling the resultant space with a dental amalgam or polymer, in essence to retain as much of the target tooth structure as possible. In more severe cases, if such decay has progressed too far, complete removal of the entire tooth may be employed. As such, early diagnosis of dental caries is of utmost importance to best guarantee the subject tooth could be properly treated in order to avoid tooth removal.
Historically, as noted above, visual diagnosis of dental caries has been undertaken by dental professionals. More recently, mechanical, radiographic, and electric probes have been utilized for such purposes as well. Despite the potential for clear visual identification of affected areas, in certain situations caries is not easy to find. For instance, decay on the approximal surface of a tooth resulting from plaque on the inter-dental spaces may not be detected by simple visual actions, or, for that matter, through mechanical probing and prodding of a subject tooth, since the approximal surfaces may not be easily seen nor easily reached by a probe. Hence, the development of certain electrical devices to provide effective measurements of tooth surface stability upon direct exposure thereto has permitted more reliability in caries diagnosis over and above strict visual acts, even when accompanied by tactile examination utilizing a common mechanical probe. Such electrical probes involve direct exposure to a tooth surface to measure any potential impedance of electrical signals throughout a tooth's structure. A change in the impedance value in the path of the electrical signal across the tooth would be a fair indication of onset of decay, thus providing a reliable measure of decay on which to make a proper diagnosis of dental caries. Such newer electrical probes have thus been proven to provide effective means to aid patients with early diagnosis of such problems when actually examined and, more succinctly, in terms of actual exposed (i.e., uncovered) teeth.
Furthermore, in terms of potential diagnosis of such caries problems, even if such dental examinations are not performed regularly on a target patient, such a person may provide a self-diagnosis through the existence of localized pain (or perhaps an increase in such pain at such a specific location) due to the presence of decaying material. Such a painful result, however, will most likely occur specifically because of direct exposure to outside elements. In any event, such visual identification, mechanical and/or electrical probing, and pain results all require the lack of any effective covering over a subject tooth, such as a crown, in order to permit proper caries diagnosis.
Clearly, visual identification of decay is impossible if the subject tooth structure is completely covered by a crown. Likewise, mechanical probing and pain indications would not be of much use as the same visual limitations exist for mechanical issues, and a patient may not suffer the same pain maladies since a crown would prevent external stimuli from causing undesirable reactions within the decaying tooth material to accord such a result. Additionally, however, the effectiveness of electrical impedance measurements as of today for determining tooth surface conditions is limited to, again, teeth that are properly exposed for such procedures, as well as the lack of a covering (such as, of course, a crown) that typically constitutes a material that will not permit effective electrical signals to be measured for such a purpose. Without access to the region susceptible to decay (i.e. via a specially designed crown) the possibility of diagnosing an underlying surface or structure within a crowned tooth has not been available within the dental field.
Additionally, the utilization of radiographic and/or X-ray procedures to properly diagnose caries potential under a crown is rather limited, either due to the crown material effecting the overall capability of the scan in question, or the difficulty in determining such a possible slight demineralization occurrence within an underlying tooth surface with such analytical methods. Basically, dental radiographs performed to detect dental caries merely show density differences in tooth structure caused by loss of calcium. As such, this method is limited in caries detection on the two accessible side surfaces of teeth. The remaining structures, particularly the occlusal, i.e. biting, surface, frequently develop considerably large carious lesions that remain undetectable by radiographic examination. These devices thus typically fail to detect a cavity until an advanced stage, and therefore are not good for early detection and treatment. Furthermore, X-ray, etc., devices are not only static by nature in terms of location, but they are also expensive to utilize. As well, such devices may expose a patient to the harmful exposure of radiation in such circumstances. Although such procedures are rather typical during dental examinations, they are still undesirable in the long run, and, again, are severely limited in their actual usefulness for caries diagnosis, particularly for sub-crown tooth structures.
As such, all of these alternative methods for caries detection have significant drawbacks and/or are limited in their capabilities to the detection of caries potential on exposed tooth surfaces. The presence of a dental crown prevents effective caries detection such that, as of today, the dental industry has not accorded any manner of compensating for such a situation, short of actually removing the crown itself. Of course, such an action is undesirable as continued removal and replacement of a crown will likely affect the dimensional stability of the remaining tooth, require further application of potentially harmful adhesives within a patient's oral cavity, and, most importantly, would prove to be rather expensive.
Thus, there exists a specific need to permit proper diagnosis of problems with teeth that are covered with crowns, particularly in terms of any potential disease or undesirable condition that may lead to crown or tooth removal if not properly treated timely. A method and device, thus, that would provide an effective means of detecting underlying tooth structure problems underneath a crown would be very important within the dental field to permit early diagnosis of potential decay problems in order to alleviate any need to undergo consequential surgical and/or implant procedures due to extensive unknown underlying tooth damage. To date, again, the dental field lacks such a beneficial method and device.